<?php
//验证码类
class VerifyCode
{
  private $charset = 'abcdefghkmnprstuvwxyzABCDEFGHKMNPRSTUVWXYZ23456789';
  //随机因子
  private $code;
  //验证码
  private $codelen;
  //验证码长度
  private $width;
  //宽度
  private $height;
  //高度
  private $img;
  //图形资源句柄
  private $font;
  //指定的字体
  private $fontsize;
  //指定字体大小
  private $fontcolor;
  //指定字体颜色

  //构造方法初始化
  public function __construct($w, $h, $fs = 24, $cl = 4)
  {
    $this->width = $w;
    $this->height = $h;
    $this->fontsize = $fs;
    $this->codelen = $cl;
    $this->font = ROOT_PATH . STATIC_DIR . DIRECTORY_SEPARATOR . FONT_DIR . DIRECTORY_SEPARATOR . 'elephant.ttf';
  }
  //生成随机码
  private function createCode()
  {
    $_len = strlen($this->charset) - 1;
    for ($i = 0; $i < $this->codelen; $i++) {
      $this->code .= $this->charset[mt_rand(0, $_len)];
    }
  }
  //生成背景
  private function createBg()
  {
    $this->img = imagecreatetruecolor($this->width, $this->height);
    $color = imagecolorallocate($this->img, 240, 240, 240);
    imagefilledrectangle($this->img, 0, $this->height, $this->width, 0, $color);
  }
  //生成文字
  private function createFont()
  {
    $_x = ceil($this->width / $this->codelen);
    for ($i = 0; $i < $this->codelen; $i++) {
      $this->fontcolor = imagecolorallocate($this->img, mt_rand(0, 156), mt_rand(0, 156), mt_rand(0, 156));
      imagettftext($this->img, $this->fontsize, mt_rand(-30, 30), $_x * $i + mt_rand(5, 10), ceil($this->height / 1.4), $this->fontcolor, $this->font, $this->code[$i]);
    }
  }
  //生成线条、雪花
  private function createLine()
  {
    for ($i = 0; $i < 6; $i++) {
      $color = imagecolorallocate($this->img, mt_rand(0, 156), mt_rand(0, 156), mt_rand(0, 156));
      imageline($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, $this->width), mt_rand(0, $this->height), $color);
    }
  }
  //输出
  private function outPut()
  {
    header('Content-type:image/jpeg');
    imagejpeg($this->img);
    imagedestroy($this->img);
  }
  //对外生成
  public function doimg($createLine = true)
  {
    ob_clean();
    $this->createBg();
    $this->createCode();
    if ($createLine) $this->createLine();
    $this->createFont();
    $this->outPut();
  }
  //获取验证码
  public function getCode()
  {
    return strtolower($this->code);
  }
}